[Galaxy S III Q&A, Help & Troubleshooting] yetep:
Hey guys,

Sorry in advance for what is no doubt something that's came up a few times in the past (as is clearly evident by the posts). I've spent a long time trying to get around the issues with this thing so hopefully I can explain what I've done so far which might help.

So, basically -

My brother had an S3. The screen broke (glass only) and he asked me to repair it. This was a few months ago. Inbetween he moved to using a Windows phone and had the S3 sitting around until he eventually decided to hand me it to repair a couple of days ago.

Now, the phone was working flawlessly prior to him turning it off and switching over to the Windows phone. The S3 sat dormant for a few months, battery out.

When I went to turn it on to test the screen and buttons to ensure that's the only fault, it wouldn't get past the boot screen.

No huge deal there.

Upon checking in recovery it was unable to mount the EFS partition. I managed to get round that.

It still wouldn't boot, so I flashed a new ROM and it booted up fine however was in "Factory mode" with IMEI starting 0049.

I've done a fair amount of searching and came to a few conclusions but essentially :

How I don't know but his EFS folder was competely corrupt and essentially contained few files, none of which were IMEI related. I have no clue how this has happened but it has.

I've managed to get the phone working ALMOST flawlessly by restoring a stock EFS backup IMG using kTool, I HAVE the phone's IMEI and serial which are printed on the phone itself. Only issue now is that the phone can't connect to any networks - because the IMEI is a default.

So, I've dug around in the stock EFS backup IMG that I was able to find (which has got the phone working great, minus mobile networks) and found that the IMEI folder contained a file "mps_code.dat". Upon opening this file it's basically empty. I assume this is because it's a stock EFS I located.

Does anyone have any clue how I can input the IMEI into this file? I tried to decompile the IMG, type it into the file and save, then recompile the IMG however kTool doesn't recognise the newly created IMG file and crashes, then restores the phone. Is there a specific tool I should be using to make the IMG and can someone root into their "mpd_code.dat" and tell me the format that it needs to be in? (I don't need or want any IMEI numbers, just the format that the file is. Just open it in a text editor through Root Explorer (root\efs\imei) and star out the IMEI if you can).

Just to clarify before anyone jumps on it - I'm NOT looking for the file(s) OR the IMEI numbers on anyones phone with that request. Simply the format in which it should be in. I'm simply trying to put the IMEI for the phone ONTO the phone so it'll recognise networks and work as it should. Everything else is absolutely fine now.

So just to clarify the options I've boiled down to :

Recompile the efs.img with the correct IMEI within - if someone can tell me how that'd be great - then restore it on kTool.

OR

Edit the on-phone mps_code.dat with the correct IMEI but I need the format (if someone could peek at theirs that'd be great).

Thank you in advance all and sorry for the story! If I manage to get this to work I'll upload a tutorial with all the relevent files required which I know will help a lot of people.

Cheers